Hypertension is a well-recognized risk factor for cardiovascular disease in adults. Furthermore, many studies have shown that there is tracking among longitudinal pediatric blood pressure determinations. An important unresolved goal in pediatric hypertension research is to define at what level of pediatric blood pressure is a child at increased risk for adult hypertension. There have been two NHLBI Task Forces in Blood Pressure Control in Children which have published reports in 1977 and 1987. One of the goals of each task force has been to define appropriate percentiles for blood pressure in children. In the Second Task Force Report, results from nine large epidemiologic studies were combined into a data base with more than 70,000 readings from which blood pressure percentiles were derived as a function of age and sex. However, many research workers have stated that height is more strongly related to blood pressure than age and have urged that Normative data for pediatric blood pressure be demarcated by height rather than age. An important goal of this application is to define sex-specific blood pressure percentiles that are a function of both age and height. Another unresolved issue in hypertension research is to define the precise age at which blood pressure distributions for different racial groups diverge. This is one of the few data bases that can address this issue since we have readings from over 43,000 white children, 23,000 black children, and 4,500 hispanic children. This will be a more than adequate sample size to test this hypothesis. If differences are found, than it is of great interest to estimate the earliest age at which racial differences in blood pressure are apparent. In summary, the previous Pediatric Task Force reports have been limited in the scope of data presented, mainly due to space limitations. We will construct blood pressure percentiles that are a function of age, sex, race, and height, which should provide a more comprehensive profile of pediatric blood pressure distributions than any previously published work.